Carburetor



' E. v. BEALS Aug. 7, 1934.

CARBURETOR Patented Aug. 7, I934 1,968,870 CARBUBETOR Erl V. Beals,Boston, Mass.

Application September 17, 1928, Serial No. 306,444 Renewed November 30,1932 Claims. (Cl. 261-50) The main object of this invention is toprovide a construction which, when adjusted'prop- V erly to suit theparticular engine to which it is applied, will function automatically tosupply 5 the engine with a minimum of fuel required for the efficientoperation of the engine. The invention also has other objects in viewwhich will appear in the course of the specification.

In the drawing annexed- Fig. 1 is a vertical sectional view of mydevice;

Fig. 2 is a plan view thereof Fig. 3 is a diagram of one form ofelectric wiring system for the heater.

Referring to the drawing annexed by refera cam which is provided with acylindrical surface 13 and an adjoining tangential surface it Bearingupon the face of this cam is a set-screw 15 carried on the end of an arm16, which arm is afiixed to a shaft 17, which shaft in turn carries anarm 18 whose forked end 19 engages between a pair of flanges 2(l-2laflixed to a plunger 22, these flanges 20-21 being spaced apartsufficiently to permit a certain amount of play of the fork l9therebetween. The fork 19 is normally held down on the flange 21 bymeans of a coil-spring 23 which surrounds an upstanding pin 24 andnormally bears down on the top side of said am 18. When in idlingposition (as shown in Fig.1), the nose of the screw 15 rests on theoblique part 14 of the cam and the fork 19 normally presses down thelower lip 21, and, when the cam is rotated in the direction of the arrowto thus open the throttle, the screw 15 rides up on the circular surface13 of the cam and thus raises the arm 18, against the action of spring23, ,to a point between the two flanges 20-21, thus permitting theplunger 22 to have a free play to a limited extent.

To manually raise the arm 18 without opening the throttle 10, I providean additional shaft 25 which is operable through the medium of a radialarm 26 and which is provided with a cam 2'! located 'under the arm 18,whereby, by rocking shaft 25, the arm 18 may be raised high enough toengage the upper flange 20 and thus raise the plunger 22, for thepurpose hereinafter set forth.

The plunger 22 works vertically in a tube 28, and the lower headed .endof the plunger is normally forced downwardly by means of a coilspring 29housed within the tube 28. This tube 28 screws up and down in a tube 30and is locked in this position by a nut 31. The tube 30 is in turnscrewed into a hole in the top of a disk 32 and is in turn locked by anut 33. The disk 32 is screwed down into an internallythreaded openingin the top wall of the mixingchamber and is locked in its adjustedposition by a nut 34. Thisdisk is hollowed out to form a chamber for adiaphragm 35 which extends entirely across the circular chamber and isclamped in position therein, at the edges of the diaphragm, by meansof adisk 36 screwed up into the ring 32. The disk 32 is provided with holes3'7 to expose the upper side of the diaphragm to atmospheric pressure atall times, while the disk 36 is provided with holes 22 to expose thelower side of the diaphra to suction pressures in the mining-either.

A disk 39 is located within the diaphragm w chamber, beneath thediaphra, and is normally pressed up against the diaphragm by means of acoil-spring til housed in a central boss formed on the disk 36, thisboss being eirtended downwardly in the form of a tube ti to 25 form aguide for a needle-valve 42, the upper end of which is attached to theaforesaid disk 39. The lower pointed end of the needle-valve cooperateswith a conical valve-seat formed in a disk 43 which is screwed down intoa cavity W in the bottom of the carburetor-casing, just below the usualventuri 42.

To form a heating-chamber for the fuel, the bottom of the mixing-chamberis extended downwardly in the form of a tube 45 which depends through ahole formed in the bottom of the float-chamber 46, the lower end of thistube-45 being externally threaded for the reception of a clamp-nut 47which clamps the bottom wall of the float-chamber against a flange 48'formed on the depending tube 45.

The disk43 is provided with an annular groove 49, and from this grooveextends inwardly a series of passages 50 which deliver air into acentral cup 51 formed in the disk t3 around the fuel-opening. Air issupplied to the groove 49 and passages 50 through a passage 52 formed inthe lower wall of the carburetor-casing and having its inletcommunicating with the intake of the carburetor at a Point outside ofthe 119 throttle. An adjustable screw 53 governs the amount of air whichis permitted to pass down through the passage 52 to the passages 49 and50.

Within the tube 45 is fitted an insulating tube 54, the upper end ofthis tube being provided with an annular shoulder 55 which rests on anupwardly-facing shoulder formed in the inner wall of the tube 45, belowthe disk 43. The disk 43 is screwed down onto the top end of theinsulating-tube 54, a sealing-gasket being interposed between these twoparts to prevent upward escape of the fuel except through thevalve-controlled inlet. The tubes 45 and 54 are provided with alinedopenings 56 to permit liquid fuel to flow from the float-chamber intothe interior of the insulating-tube 54.

Within the tube 54 is mounted an electrical heating-unit consisting ofan upstanding rod 57 insulatedly supported within .a plug 58 screwedinto the lowerrend otthe insulatingtube 54. A nicrome heating-wire 59 iselectrically connected to the plug 58 at one end and to the upper end ofthe rod 5'7 at the other end. To the upstanding end of the rod 57 isconnected, in any suitable manner, an electrical conductor 60, and tothe plug 58 is connected the other terminal 61 of an electrical circuit,

so that, when current is supplied to the circuit 60-61, the wire 59 willbe heated, thus heating the fuel in the chamber formed bytheinsulating-tube 54. An insulating washer 62 is arranged between theheaded fiange of the plug 58 and the nut 4'7, the lower end of tube 45and the lower end of tube 54, a suitable sealinggasket being employed toinsure against leakage of the liquid fuel. Another insulating washer 63is desirably employed between the clampnuts 64 and the bottom end of theplug 58. The insulating tube 54 is desirably locked in position by meansof a set-screw 65.

The electrical heating-device herein shown and described issubstantially the same as the one disclosed in my co-pending applicationSerial No. 216,264, filed August 29, 1927, which has since matured intoPatent No. 1,739,818 dated Dec. 17, 1929. In the present construction,however, I make the tube 54 of heat-insulating material to thus do awaywith the dead-air space shown in my pending application and to moreeffectively conserve the heat generated by the electric wire. In thisconstruction, I also form the valve-seat in a separate metal disk fittedinto the bottom of the mixing-chamber rather than in the integral top ofthe inner tube. In this construction, I also screw the closure-plug 58directly into the insulating tube 54 rather than connect the same' tothe lower end of said tube by means of an insulating tube, as in thepending case. The present construction is more eflicient in conservingheat and is more easily manufactured, and, besides, more effectuallyseals the liquid fuel against escape either downwardly out of thefloat-chamber or upwardly into the mixing-chamber. In the pending case,I show a series circuit arrangement for controlling the supply ofcurrent to the heating-wire, whereas in the present case (in Fig. 3) Ishow a parallel system of connection. In the present system, the plug 58is grounded in the carburetor-casing, and I connect the conductor 60from the generator G to the terminal .57, the battery conductor 67 beingconnected to this same terminal and provided with a dash-switch S forpriming with the battery 68, the other terminal of the battery beinggrounded. The conductor 6'7 is connected to the generator through arelay cutout R. The other terminal of the generator is connected toground through a manually-controlled rheostat 69. The relay cutout R(which exists in all battery-charging systems) works to prevent thebattery from acting on the heating-unit when the engine is idle and theswitch S is open. The dash-switch S, manually controlled, is a plaintwo-pole switch instead of the grounding switch illustrated in thepending application.

I have shown my metering devices in association with my improvedelectrical heater arrangement, but it will be understood that mymetering arrangement may be used with any other type of carburetorwithout departing from the scope of my patent.

In Fig. 1, the parts are shown in idling position, in which position thethrottle 10 is closed, the adjusting screw 15 resting on the cam-face14, and the two springs 23 and 29 are combining their strength to forcethe diaphragm-disk 39 down against the stop-disk 36, thus holding theneedle positively in idling position. ,This idling position of theneedle is determined by screwing the ring 32 (which carries the entiremetering unit) up or down in the wall of the carburetor, the ring beinglocked in nicely adjusted position by means of the nut 34. The idlingair is mostly taken in through the duct 52 which is controlled asheretofore stated, by the adjusting-screw 53. This supply of air isdelivered through the radial ducts 50 into the cup 51, close to thepoint of emission of the fuel, so as to thereby insure a thoroughintermingling of the gas and air.

When the engine is to be primed, the shaft 25 is rocked to raise thearm- 18 up against the flange 20, to thus release the diaphragm of thepressure of the two springs 23 and 29, thereby allowing the spring 40 toautomatically raise the diaphragm and with it the needle, therebyinsuring a rich mixture for starting the engine.

The diaphragm is placed between two opposing springs (the top oneadjustable), so as to be able to accommodate or attune its action to thediiferent engines which exert varying suction pressures. The tension ofspring 40 is greater than 29, so that the diaphragm and needle wouldremain in the uppermost position when the engine is stopped and theintake suction ceases, if it were not held down positively by the idlingmechanism already described.

When the engine is running, this idling restraint is automatically cutout by action of the cam 13, as already stated, leaving the diaphragm,as adjusted, free to move up or down according to the absolute pressuresof the manifold. In fact, the diaphragm and needle float upon the intakevacuum. Since the butterfly is in the position of a choke, the, suctiondecreases as it is opened, and, vice versa, increases as the butterfiyis closed. Dynamometer tests show that, with the throttle wide open, thevacuum is as low as two inches of mercury; and, with the butterflyclosed (as during the idling period) as high as seventeen inches ofmercury. From these facts, it will readily be seen that the absolutepressures are utilized in this invention as a measure of the amount ofair passing, and that the diaphragm, controlled by such pressures,automatically positions the needle settings in accordance therewith to.maintain the air-fuel ratio. Now, since there is no buretors.

damper of any sort between the manifold and the fuel-orifice, thesuction of the engine has a direct pull on the fuel, which pull isintensified as the throttleis being closed, so that the fuelorifice ismuch more minute than in jet car- For instance, the orifice for idlingpurposes is but little more than that of a fith inch drill. This extremesmallness of the orifice acts beneficially in breaking up the fuel morefinely due to its extra high velocity. This fact, coupled with the extravolatility given to the fuel by the electric heat unit, is the means ofobtaining a homogeneity of mixture far in excess of any jet or wetmixture device. This diaphragm-controlled needle is in fact equivalentto an infinite number of jets brought into play successively andautomatically in accordance with engine requirements.

The engine is started with the butterfly closed. This puts the wholesuction of the engine on the fuel, the same as closing the choke withthe jet carburetor; The suction also brings down the diaphragm and theneedle to the idling position, where they are held positively by theforked arm 18, as described. When the engine is cold and only then, thearm 18 is raised as described and in turn raises plunger 20 so as totake away entirely the function of spring 29. This act leaves spring 40unopposed and its tension is sufficient then to overcome the downwardsuction of the diaphragm. The needle finds itself in the uppermostposition under these circumstances and gives the required orificeopeningfor the proper richness of mixture to insure prompt and sure startingunder all weather conditions. As soon. as the butterfly is opened forrunning conditions, arm 18 is manually (through arm 26) dropped down to.neutral position and held there by the cam mechanism described andspring 29 is again brought into functional relation with the diaphragm,and the needle can then be seen to be fluctuating with the draughts ofthe engine.

In accordance with the provisions of the patent statutes, I have hereindescribed the principle of operation of my invention, together with theapparatus which I now considerto represent the best embodiments thereof,but I desire to have it understood that the apparatus disclosed is onlyillustrative and that the invention can be carried out by other means.Also, while it is designed to use the various features and elements inthe combinations and relations described, some of these may be alteredand others omitted and some of the features of each modification may beembodied in the others without interfering with the more general resultsoutlined, and the invention extends to such use.

What I claim as new is:

1. In a carburetor for internal-combustion engines, a throttle arrangedin the air-intake, and means whereby idling air is taken from in frontof the throttle and delivered to the mixingchamber, adjacent thefuel-inlet, the delivery means at the fuel-inlet consisting of acupshaped disk in the bottom of which the inlet is formed, said diskbeing provided with a plurality of radial ports delivering air into saidcup.

2. A carburetor embodying a needle-fuel-feed and devices for adjustingthe, idling position of the needle, a throttle in the intake-side of thecarburetor, and means whereby when said throttle is open the needle willbe released from idling position and become subject to the pressure inthe intake-manifold, said means embodying a diaphragm andcounter-balancing springs on opposite sides thereof.

3. A carburetor embodying a needle fuel-feed and devices for adjustingthe idling position of the needle, a throttle in the intake-side of thecarburetor, and means whereby when said throttle is open the needle willbe released from idling position and become subject to the pressure inthe intake-manifold, said means embodying a bodily-adjustable diaphragmopen at one side to the atmosphere and at the other side to suction, andcounter-balancing springs on opposite sides of the diaphragm.

4. A carburetor embodying a needle fuel-feed and devices for adjustingthe idling position of diaphragm is bodily adjustable together with.

the needle, a spring pressing the needle toward the diaphragm, and acounter-balancing spring arranged at the other side of the diaphragm.

5. In a carburetor, a mixing chamber having a main air inlet and a fuelinlet, a valve in said air inlet, a fuel valve in said fuel inlet, adiaphragm connected to said fuel valve for operation thereof, saiddiaphragm being exposed on one side to pressure conditions within saidchamber and on the other side to the atmosphere, the arrangement beingsuch that pressures in the chamber lower than atmospheric pressure tendto actuate the diaphragm to close said fuel valve, spring means tendingto press said diaphragm outwardly against atmospheric pressure, an outerspring tending to press the diaphragm inwardly, and accessible means foradjusting the outer spring.

ERL V. BEALS.

